Few guys still use them. Back in the day, chips sucked, and big injectors weren't very street friendly. So the seventh injector helped. Now we have great chip guys like Bailey and Steve, and can run big injectors all the time, like I do. I don't like 7th inj. systems because you are trying to flow fuel through a manifold designed for air, and it doesn't flow well. For the price of the kit, you could get some good injectors and a chip. HTH